Abstract: Cobalt-based catalysts supported on ordered mesoporous carbon (Co/OMC) were modified with Mn and Zr promoters by the co-impregnation method. The cobalt-based catalysts were characterized by XRD, N₂ sorption, H₂-TPR, H₂/CO-TPD and XPS; the promoting effects of Mn and Zr on the catalytic performance of Co/OMC in Fischer-Tropsch synthesis (FTS) were investigated in a fixed-bed reactor. The results indicate that the addition of either Mn or Zr can greatly reduce the selectivity to CH₄ for FTS over Co/OMC. Moreover, Mn as a promoter can enhance the selectivity to C_2-4 hydrocarbons and the olefin/paraffin ratio, whereas Zr promotes the dispersion of cobalt species and increases the number of active Co sites, leading to a significant increase in the FTS activity and selectivity to C₅₊ hydrocarbons.